Gates, 64, has a net worth of $110 billion and he knows how to make the most of it. While he has some indulgences — like a Washington estate worth $125 million, a private airplane, and a luxury-car collection — they make up only a fraction of his massive fortune.

In fact, Gates and his wife, Melinda, previously said it’s unfair they’re so rich. Instead of spending billions on themselves, they often donate it to charity through the Bill and Melinda Gates Foundation. They’ve also pledged to give away most of their fortune through the Giving Pledge, which they launched in 2010.

Keep reading for a look at how Gates spends his billions.

Bill Gates is once again the richest person in the world. Here’s how he spends his $110 billion fortune, from a luxury-car collection to incredible real estate. slides

Bill Gates is once again the richest person in the world. Here’s how he spends his $110 billion fortune, from a luxury-car collection to incredible real estate. slides

Bill Gates, the cofounder of Microsoft, has an estimated net worth of $110 billion, making him the world's richest person.

On Friday, Gates reclaimed the title of the world's richest person from Jeff Bezos on Bloomberg's Billionaires Index after Microsoft beat out Amazon for a $10 billion cloud-computing contract from the Pentagon. The contract spiked Microsoft's shares and sank Amazon's.

But Gates' splurges are only a fraction of his massive fortune. He previously told The Telegraph, "I have no use for money." Instead, he often donates to or invests his money in good causes.

Gates previously invested in Amyris, a synthetic-biology company that originally produced precursors to malaria drugs and hydrocarbon-based biofuel. Today, it focuses on health through fragrances, skincare, and sweetener.

He continued these efforts by recently investing $30 million with a group of investors into the Diagnostics Accelerator, a "venture philanthropy" fund to diagnose Alzheimer's earlier.

Gates and Melinda are huge on philanthropy. They were recently named the most generous philanthropists in the US by The Chronicle of Philanthropy, having donated more than $36 billion to charitable causes through the Bill and Melinda Gates Foundation.

In 2017, they donated $4.78 billion, mostly to projects run by the Bill and Melinda Gates Foundation.

They donated more than $2 billion in 2016 to causes related to global health and development and US education.

They've pledged about $2 billion to defeat malaria, donated more than $50 million to fight Ebola, and pledged $38 million to a Japanese pharmaceutical company working to create a low-cost polio vaccine.

On October 28, 2019, Melinda shared an Instagram post of Gates wearing a goofy birthday hat for his 64th birthday. In the caption, she explained that Gates first wore the hat by request of his then-pre-school-aged daughter, Jen, 20 years ago.